This invention relates to an apparatus for analyzing agglutination patterns produced in response to an immunological agglutination reaction, and more particularly to apparatus for identifying various kinds of blood types with the aid of agglutination patterns of blood corpuscles or for detecting various kinds of antibodies and various antigens in sample solutions (like viruses, proteins or the like) with the aid of agglutination patterns of not only blood corpuscles but also of particles of materials such as latex, carbon or the like.
In known analyzing apparatus due to the agglutinating reaction, reaction vessels and analyzing steps are different for respective components to be analyzed. For instance, in a known manual apparatus for judging the blood type of ABO system, use was made of test tubes as the reaction vessels. In this apparatus a sample blood is first centrifuged to separate red blood cells and serum from each other, and then a given amount of blood cells is mixed with a diluent to form a blood cell suspension of 2 to 5%. Then, a given amount of the blood cell suspension is delivered into a test tube into which anti-A-serum of anti-B-serum is also distributed. After the blood cells have been centrifuged, the test tube is shaken and it is confirmed with the naked eye whether or not agglutination is formed. In this case, the sample blood which produces agglutination together with A-type antibody, but does not produce agglutination together with B-type antibody is identified as A-type, the sample blood which produces agglutination exclusively with B-type antibody is judged to be B-type, the sample blood which forms agglutination with both A-type and B-type antibodies is determined to be AB-type, and sample blood which does not produce agglutination with either A-type and B-type antibodies is judged as O-type.
In order to detect and measure HBs antigen, a method has been proposed which makes use of a plastic plate, called a microplate, provided with a number of wells, i.e. reaction vessels each having a conical base surface. This conventional method makes use of a microplate having 10.times.12 wells, for example, and detects and prescribes the HBs antigen by the following procedure.
(1) Buffer solution specially prescribed for R-PHA method is introduced into each well of the microplate one drop (0.025 ml) at a time. PA1 (2) A test serum (0.025 ml) is added to the first well of a row. By using a diluter, the doubling dilution is performed along the row up to the last (tenth) well. PA1 (3) One drop of R-PHA buffer (0.025 ml) is added to a first row and one drop of R-PHA inhibition solution is added to a second row. PA1 (4) After the mixtures thus treated have been sufficiently agitated by a micromixer for 10 seconds, incurvation is effected for one hour at 37.degree. C. PA1 (5) A drop of R-PHA cells of 1% suspension (0.025 ml) is added to each well. PA1 (6) The mixtures are agitated by the micromixer for ten seconds to suspend the R-PHA cells uniformly. PA1 (7) After the mixtures thus treated have been made stationary at room temperature for one hour, agglutination patterns are detected. PA1 means for carrying a plurality of sample tubes which accommodate blood samples to be analyzed therein at a delivery position in turn, PA1 means for forming a plurality of diluent blood samples by diluting the blood samples accommodated in the sample tubes at the delivery position, PA1 a reactive reaction line including a plurality of reaction line passages, PA1 means for feeding microplates successively from input side of the reaction line, PA1 means for delivering given amounts of the diluted blood samples into at least one reaction vessel of the microplates supplied to the reaction line, PA1 means for delivering given amounts of the reagents into the reaction vessels according to analysis-items, PA1 means for transporting microplates having blood samples and reagents delivered in the reaction vessels along the reaction line in a substantially non-vibrating manner, PA1 means for photoelectrically detecting agglutination patterns formed on the bottom surfaces of the reaction vessels at the predetermined position of the reaction line by subjecting to antigen and antibody combination reaction during transporting the blood sample and the reagent along the reaction line in a substantially non-vibrating manner after delivering thereinto the reaction vessels, PA1 means for receiving the detection signal to effect an analysis due to the existence or non-existence of the agglutination patterns, and PA1 means for discharging the microplates from an exit of the reaction line after the agglutination patterns of all the reaction vessels in the microplate have been detected. PA1 a delivery transporting means for transporting respective trains of reaction vessel to a required delivery position, PA1 first sending means for sending delivered microplate to a reaction line transporting means, PA1 a reaction line transporting means for receiving microplates in turn in the horizontal state and for intermittently transporting the microplates in the vertical direction, PA1 a measurement transporting means for transporting the microplate to a measuring position from the reaction line, and PA1 a second sending means for sending measured microplate to a discharging position.
In the T-PHA system for syphilis, different diluents of a sample serum are formed in the microplate and a reagent prepared by bonding syphilis viruse with red blood cells of sheep is added to the serum diluents. After natural segmentation, it is confirmed with naked eyes whether or not agglutination is formed.
As described above, in the analyzing apparatuses due to immunological agglutination reaction different kinds of reaction vessels are used depending upon the test items and further successive steps are also different for respective items.
There has also been known a microtitor apparatus in which use is made of the microplate as the reaction vessels and steps are partially automated. In this apparatus, delivery of samples and reagents and detection of agglutination are carried out automatically, but other steps are effected manually. This is due to the fact that in the case of using the microplate, mechanism and operations are liable to be complicated and thus, it is extremely difficult to effect all the steps automatically. Further, the microtitor method has several disadvantages. Since the sample serum is delivered quantitatively with the aid of capillary phenomenon, it is necessary to first deliver diluent into each well in the microplate and then a tip of dilutor onto which a sample has been applied is immersed into the diluent to mix the serum and diluent. Such a step is very complicated as compared with normal delivery steps in the analyzing apparatuses and thus could be controlled only by means of complicated mechanisms. Further, the delivery amount is made always constant, because the capillary action is utilized and thus, the delivery amount could not be adjusted at will. Further, the mixed solution is applied to the dilutor and the sample is partially wasted. This becomes a serious drawback in a multi-item analyzer.
Moreover, if the delivery of the blood cell sample is effected before the serum sample delivery, an indefinite amount of the blood cell sample might be removed from the well. Therefore, in the microtitor system, the diluent delivery, serum delivery and blood cell delivery have to be performed in this order and thus, the mechanical arrangement or design might be restricted. Further in the microtitor method, since use is made of the blood cell suspension of about 1%, the operation is liable to be very complicated as compared with the test tube method described above.
In a conventional method of identifying blood types, for example, which has heretofore been proposed, use was made of a winecup-shaped reaction vessel into which was quantitatively introduced a sample solution, i.e. 2 to 5% of test blood corpuscles suspended in saline solution, and a specified antiserum, i.e. anti-A- or anti-B-serum. Then, the mixture was held stationary for reaction between blood corpuscles and antiserum. Subsequently, it was centrifuged to sediment blood corpuscles. Then, the reaction vessel was rapidly wobbled such that the sedimented blood corpuscles were forcedly separated one from the other and then relatively slowly wobbled so as to collect the clumped compositions in the center portion of the base surface of the vessel and form settling patterns, thereby photometrically detecting these patterns.
Such conventional blood type identifying method in which sedimentation is effected and then the reaction vessel is rapidly wobbled so as to separate the sedimented blood corpuscles from the base surface of the vessel can only be applied to the analysis of regular ABO blood type, which shows stong agglutination, but could not be applied to many other immunological agglutination reactions which show weak agglutination, for example, a method of determining Rh blood subtype or detecting various kinds of incomplete antibodies. That is, if the agglutination reaction is weak, the blood corpuscles or the like which have been clumped together become separated one from other when the reaction vessel is wobbled, and as a result, the particles are not collected in the center portion of the reaction vessel.
Further, in this known apparatus, in order to effect the accurate judgement of the blood type, it is necessary to prepare a substantial amount of the sample blood cells and thus, required amounts of standard antiserums are increased accordingly. Nowadays, a very large number of test items are to be effected for respective patients and thus, required amounts of the sample blood for respective items must be decreased as small as possible.
In known analyzing apparatus due to the agglutinating reaction, the reaction line for holding microplate over the time necessary to reaction has horizontally arranged microplates which are transported in the vertical direction by the belt conveyor so that the apparatus becomes large in construction, and dusts or the like are fallen on the microplate because of planer arrangement resulting in an affection in judgement. In order to form the reaction patterns the plate must be placed quietly, but the plate is transported in turn even during plate holding thereby subjecting it to vibration from the belt resulting in an affection of reaction pattern formation.
In the case of the direct judgement of ABO blood type blood cells are used as sample and in the case of the indirect judgement of ABO blood type and the analysis of antibody screening serums are used as sample. In this case the concentration of blood cell suspension is 1.5% and the concentration of serum is 25% so that the blood cell suspension has very high diluting magnification. In case of forming the diluted suspension having high diluting magnification there is no problem when the suspension is completely agitated by hand, but in the automatic analyzing apparatus diluted suspension of required concentration cannot often be obtained since a part of blood cell adhered to the wall of vessel. In the automatic analyzing apparatus the delivering amount of blood cell suspension and serum diluent for judgement and analysis is very small, such as 25 .mu.l so that the effect of blood cell amount in the delivered blood cell suspension on agglutination reaction becomes large resulting in a cause of erroneous judgement. If agitating device is provided in the automatic analyzing apparatus the above problem can be solved, but the apparatus becomes complicated in construction and expensive.
The method of feeding sample vessels in the known apparatus comprises the steps of directly housing a plurality of sample vessels in each partition of cassette trays partitioned into a plurality of partitions, conveying these sample vessels into the automatic analyzing apparatus by means of the belt conveyor, after a predetermined work on samples in the sample vessels in the automatic analyzing apparatus, sending the used sample vessels into another empty cassette tray arranged at the end opposite to the sample vessel supply side of the belt conveyor.
In the method of feeding sample vessels in this known automatic analyzing apparatus, however, there are required both the cassette tray for feeding sample vessels to the belt conveyor and the empty cassette tray for housing the used sample vessels discharged from the belt conveyor, so as to occupy much space and to enlarge the whole apparatus. In relation to the work for treating samples in the automatic analyzing apparatus, the cassette tray on the feed side of the sample vessel is usually positioned apart from the cassette tray on the discharge side of the used sample vessel, and as a result, it is necessary to connect therebetween another transporting mechanism, which makes the construction of the apparatus complicated.